Various abrading tools using abrasive belts or abrasive sheets are known. Many of these tools are power operated. A typical power operated abrading tool has an abrasive belt or an abrasive sheet secured thereon and performs the abrading function by vibration or rotation. While such power tools are useful for many purposes, there has always been the need for good hand operated abrading tools. A good hand operated tool should be simple and easy to use. However, many hand operated abrading tool available on the market are not configured to accomplish the type of fine abrasion that is required in some applications.
A basic description of such tools is best accomplished by reviewing a number of patents issued in this area.
U.S. Pat. No. 2,457,466 (Hanna) discloses a hand operated abrader having a supporting block and a sharply curved push bar. One end of the supporting block has a flat portion. An abrasive strip in continuous form envelops the supporting block. The push bar has a pair of arms disposed in two holes in the flat portion of the supporting block. A coil spring loosely surrounds each of the arms and has one end seated against the shoulder in the appropriate hole and the other end active against the push bar, thereby holding the abrasive strip to the supporting block.
U.S. Pat. No. 4,242,843 (Phillips) discloses an abrading tool having an endless abrasive belt wrapped around an elongated block that has a wedge cavity at one end. A wedge is inserted into the wedge cavity to apply tension on the abrasive belt and secure the abrasive belt to the elongated block.
U.S. Pat. No. 1,844,998 (Walker) discloses an abrading sheet holder having a major section and a substantially flat tongue section. The major section has a broad shallow channel. A slot on one side of the channel receives one end of an abrading sheet. The other end of the abrading sheet is disposed in a slot on the tongue section. A concave pocket extends throughout the length of the channel opposite to the slot in the channel. A rounded side edge opposite to the slot in the tongue section fits into the concave pocket in the channel. Dowel pins connects the tongue section to the major section near the slots.
U.S. Pat. No. 2,413,147 (Lawrence) discloses a hand sander having a body portion and a wedge block. Two ends of a sanding strip are positioned in two slots on the body portion, one slot in one end of the body portion and the other slot in the upper surface of the body portion. The intermediate portion of the sanding strip is stretched over the lower surface of the body portion. The wedge block fits into the slot in the upper surface of the body portion, securing the sanding strip to the body portion.
A problem with these and other prior art abrading tools is that it is not very easy to remove and replace abrasive belts or abrasive sheets. In addition, they are complicated and, therefore, not very cost efficient.
Accordingly, it would be advantageous to have abrading tools using abrasive sheets or endless abrasive belts that are simple and cost efficient. It is desirable for the abrading tools to allow simple and easy adjustment of the tensions in the abrasive sheets or belts. It is also desirable if the abrasive sheets of belts can be easily removed and replaced. Furthermore, where a significant amount of abrading is required, the comfortable use of the tools and excellent control of the tools are also important desirable factors.